A Novel Picornavirus Discovered in White Leg Shrimp Penaeus vannamei

Abstract

Global shrimp farming is increasingly threatened by various emerging viruses. In the present study, a novel picornavirus, <i>Penaeus vannamei</i> picornavirus (<i>Pv</i>PV), was discovered in moribund White leg shrimp (<i>Penaeus vannamei</i>) collected from farm ponds in China in 2015. Similar to most picornaviruses, <i>Pv</i>PV is non-enveloped RNA virus, with a particle diameter of approximately 30 nm. The sequence of the positive single-stranded RNA genome with a length of 10,550 nts was characterized by using genome sequencing and reverse transcription PCR. The existence of <i>Pv</i>PV related proteins was further proved by confirmation of viral amino acid sequences, using mass spectrometry analysis. Phylogenetic analysis based on the full-length genomic sequence revealed that <i>Pv</i>PV was more closely related to the Wenzhou shrimp virus 8 than to any other dicistroviruses in the order <i>Picornavirales</i>. Genomic sequence conservative domain prediction analysis showed that the <i>Pv</i>PV genome encoded a large tegument protein UL36, which was unique among the known dicistroviruses and different from other dicistroviruses. According to these molecular features, we proposed that <i>Pv</i>PV is a new species in the family <i>Dicistroviridae</i>. This study reported the first whole-genome sequence of a novel and distinct picornavirus in crustaceans, <i>Pv</i>PV, and suggests that further studies of <i>Pv</i>PV would be helpful in understanding its evolution and potential pathogenicity, as well as in developing diagnostic techniques.